New to forum & Rochester Carb Issues

[72CampSpecial]

Hello-- Im new to the forum and wanted to say HI...I recently purchased a 1972 C20 Custom Camper, 350 V8, Quadrajet Carb and 350 AT. Ill post a pic later..was in decent shape, new tires, good exhaust, bench seat is intact. pretty straight body and the price was right ($1000)

Carb # 17057512 (i think..the first 5 # are almost not readable)

Thus far: Changes the AT pan gasket, new wires, plugs, adjusted the timing and reinstalled the choke coil spring properly (i think). Choke plate (integral choke) now snaps shut when i tap the throttle first thing in the AM. (didnt close at all prior to me pulling the coil spring off and re-installing.. i dont think it was hooked on the tang (?) inside the choke housing). i pulled the vacuum line off the choke pull off, depressed it and plugged the line and the choke pull off stays down (so i believe its working right?) And visually at first start up have watched it flutter (pull in) back and forth. I dont think the carb has even been re-built.

Issue: Now it turns over instantly first thing in the morning, but after about 10-15 seconds it starts to gargle/hesitate.. i dont think the choke plate is opening at all after it starts (choke pull off issue?)..if i flutter the gas peddle just right i can keep it running and after 20-30 seconds she will idle on her own w/no issue. If i dont get the gargle to stop it dies and then i have a heck of a time getting it to restart.

Once its idle for a few minutes and i drive away i have a huge flat spot in the carb at low speeds and the carb "Pops" (like a back fire.. but not the loud bang out the tail pipe) when its cold.. for at least the first 10-15 min of driving if i try to accelerate fast.

After she is good and warm the engine responds good, but lacks any real power. I can mash the pedal and get it to shift gears and get some speed, but for a V8 its very sluggish.

...So, where do i start?? Ive been reading all the manuals i can find, and thinking that i need to figure out how to get the carb back to some sort of a starting point.

[Lee H]

Welcome to the board. Your symptoms are classic for a Quadrajet that needs rebuilt. 17057512 was used on 75-77 Chevy & GMC Trucks with 454 for California. This carb can easily be rebuilt and give you years of trouble free operation. You can rebuild it your self, I would recommend getting the Cliff Ruggles book, How to rebuild and modify Rochester Quadrajet Carburetors. Or you can have that on professionally rebuilt.

[72CampSpecial]

Thanks Lee H...I've been considering a rebuild..from what I've read it doesn't look tooooo bad/hard
Any recommendations on who to buy a rebuild kit through..there sends to be a lot of people offering then..any issue with a Napa kit?
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[Lee H]

Ethanol is the main issue. Most if not all the DIY auto parts houses kits are not ethanol compatible, even though they say they are. Ethanol swells the accelerator pump causing the dreaded off idle stumble within a few days. I get my kits from Cliff Ruggles. Do a little research, get a book, also there are some good tutorials both written and videos on line, and you should be able to do it. You can also check out the professional re-builders, like Ruggles or Sean Murphy Induction, a little spendy but well worth the price for years of trouble free operation.

[airdale94]

Your choke just needs adjusting. Probably why it was unhooked. You adjust it by bending the rod. Or probably in your case (to rich) un-bending it.

[72CampSpecial]

Ordered carb kit, meetering rods, jets, book and spoke with Cliff Ruggles on the phone today..

He even filled the order and mailed it today! Should be here later this week... then ill start the re-build!

[Lee H]

Lets us know how it works out. With all that you should have a great running carb in no time.

[slikside]

I did this about 2 years ago. What a difference!
You will not be sorry.

What I did was to take it real slow. Don't rush.
And take a lot of pics to reference on reassembly.

Cliff is the man.
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[mking]

Welcome to the board.
Sounds like you're headed in the right direction.
Be sure to check the throttle shafts for play. If they get too loose they can cause it to hesitate and backfire. Primaries are usually the worst.
If you need to have bushings installed, I'd recommended finding someone who has the right equipment and has done it before. I found a guy locally that does nothing but carbs. There are probably some guys on here that came tell you about others.
Good Luck
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[72CampSpecial]

I borrowed this pic from another thread.. Does anyone have a close up of the Choke Pull off same angle as this pic but closer. Right below the adjustment screw on the pull off there is a lever (Tang?)...at no time does it engage or touch anything. I think it might be bent on mine or the tang/lever its supposed to touch is bent..

Basically i need to know how all the levers/tangs should look on the passendger side of the carb behind the pull off and choke..does that make sense?

This pic but closer up view of the Chok and Pull off..


Also is it the screw on the pull-off (that is in this pic right above the choke) the one you adjust to get your pull off to open sooner/latter? I need my choke to open sooner, its not "popping" open 1/4 right after the truck starts.
thanks!

[Wrenchbender Ret]

The tang contacts the choke linkage to open the choke part way when the engine starts. The screw adjusts the amount of opening. There is generally a rod that goes from the pulloff to the secondary butterflies to prevent them from opening untill the vacuum falls off. The secondary pulloff opens the choke also. With tha round choke like that has you can easily change to an electric choke if you wanted.